Hackers may have had access to personal information for about 600 UCSF patients as a result of an Internet "phishing" scam, campus officials said Tuesday.

The security breach occurred in September when a faculty physician in the UCSF School of Medicine provided a user name and password in response to a scam e-mail message. The e-mail had been sent by hackers and made to look as though it came from UCSF workers who are responsible for upgrading security on internal computer servers.

A UCSF audit in October found that e-mails in the physician's account included personal information about patients, including demographic and clinical data, and the Social Security numbers of four patients. It is unknown whether hackers actually accessed the e-mails.

The patients have all been notified of the security breach.

Phishing scams are designed to get people to reveal private information - such as Social Security numbers, credit card information and passwords - when they reply to e-mails that pretend to come from legitimate organizations.

For years, financial institutions and other corporations have been educating people to be cautious of such scams and wary of revealing private information on the Internet.

In response to the latest scam, UCSF officials said the university has been re-educating employees about protecting their user names and passwords.